The invention relates to a method of and device for finishing cage windows in a ball cage for a constant velocity universal ball joint, which ball cage has the shape of an annular member which comprises two parallel annular edges and a convex outer face and out of which there are punched uniformly circumferentially distributed cage windows each having two circumferentially extending edges. The shape of the convex outer face of the annular member can be varied within wide limits in that, for example, it is possible to provide a spherical outer curvature or the shape of a double cone. The wall thickness of the cage is approximately constant, but it can comprise different thickness ratios within the range of a small-numbered multiple.
Following the assembly of a constant velocity universal ball joint, the inner edges of the cage windows constitute running faces for the balls guided in the cage windows. The quality of the running faces thus has to be good, both in respect of their peak-to-valley height and the parallelity of their lateral lines. The running faces also have to comprise a sufficient surface hardness.
In the case of prior art methods of finishing cage windows, punched cage windows whose edges are inadequate in respect of surface quality and parallelity, are first broached or milled, then hardened, and after having been hardened they are ground. Such a method is expensive and time-consuming, especially as the workpiece has to be re-clamped several times.
It is therefore the object of the invention to provide a simplified and cost-effective method of finishing the cage windows, as well as a suitable tool.